Tractor.



0. A. HOLLIS.

TRACTOR.

APPLIOATION FILED 11u19, 1911. RENBWBD 1,111.9. 1913.

Lg. Y l Patented Aug.12,1913.

NVENTOR.

fromm 125,

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der to guide the tudinal flanges, the two being mounted to coperatie by burying themselves in the earth, substantially as described.

.2. The combination with a driving cnginc and suitable-gearing, of a revolving drum having helical flanges to directly engage in the earth, and a supplemental drum with approximately longitudinal anges mounted in alinement with the helical drum and having means to rotate it at will in orline cf travel of the helical drum.

3. A traction engine comprising a frame, a driving engine, a longitudinal shaft in the frame, a drum revolving on'said shaft and driven by said engine and having helical flanges thereon adapted to engage in vthe earth, and on the same shaft a guiding drum with longitudinally arranged flanges engaging the earth7 and a worm gear device for altering the relativel position of said supplemental drum, whereby the two drums may travel forward rections by direct engagement with the earth as a resistance abutment, and the supplemental drum travels in the path of cylindrical form created by the driving drum in its motion, substantially as described.

In testimony whereof I affix my signature in the presence of two witnesses.

OTIS A. HOLLS. Vitnesses:

MAX H. SnoLovITz, CHRISTINA T. Hoon.

and in controllable di 

